Electric-arc lamp.



K. VON DREGER.

ELECTRIC ARC LAMP.

APPLICATION FILED Jun so, 1908.

1,026,568. Patented May 14, 1912.

mmwsm lNl/EN T011 1 W MK? UNITED STATES PATENT OFFICE.

KARL voN DREGER, or BERLIN, GERMANY, ASSIGNOR TO :GE'sEL soHAr'r w ves- WERTUNG TECHNISCHER PATENTE MIT, BEsoHB-ANKTER AFTUNG, or .BREMEN,

GERMANY.

ELECTRIC-ARC LAMP.

Specification of Letters Patent.

, Patented Maw, 1912.

Application filed June 30, 1908. Serial No. 441,263.

No; 92, in BerlinyGermany, as'ubject of the Emperor of Austria-Hungary, have invented certain new'and useful Improvements in Electric-Arc-'Lamps,'-'of which the following .is a'full, clear, and exact-description.

The present invention relates to electric a-rclamps and has for its object the disposition of the carbons or'electrodes therein in such fashion that the light from thearcs shall be enabled to pass unobstructedly downward in practically all directions.

Another object of the present invention is to provide means for steadying the flame of the arc to substantially obviate flickering. To this end, the carbons are preferably arranged one above the other and a preferably'substantially flat plate for steadying the flaming arc is disposed above the upper carbon and out of contact therewith. The upper carbon is preferably the positive one: and it is caused to project somewhat beyond the negative carbon, which may be effected initially when supplying the lamp with freshcarbons; but it is obvious, of course, that other means may be employed to this end.

The ratio between the cross-sections of the respective carbons is preferably such that the carbons will burn equally per unit of time; which ratio will vary according to, the kind or kinds of carbon used,a.nd should be determined by experiment. Owing to the fact that the positive carbon burning tip nornially projects beyond the burningtip of the negative carbon, the crater of the latter is able to emit the light produced in it, and indeed, that from practically the entire length of the are, freely and unobstructedly downward. Ordinarily the carbons are so arranged that they are located inthe same vertical plane, one above the other, and both are preferably disposed substantially horizontal.

The contacting of thecarbons, which is necessary for striking the arc, may be produced by causing the point of one of said carbons to move toward the'point of the other when the lamp is switched on, but I do not desire to be limited to any particular means for striking the arc.

In the accompanying drawings I have ex- -of exemplificationand that .appended hereto, since Lam awa vention, but it will be understogd construction therem shown is merely? *l' to be limited only-by the scope 'of" x {e s many changes and modlficatl ns may be made'herein without departing from spirit of my invention. 7

In said drawings like reference characters designate like parts throughout therespective views. '5 fj'l; Figure 1 is a somewhat diagrammaticsection of an arc-lamp provided with two se'ts of carbons. Fig. 2 illustrates, insect-ion, a modification of said lamp, means -being shown for spacingthe carbons apart. Fig.

3 is a detail view of the carbon separating device.

Referring first to Fig. 1, a supporting, and preferably also shielding, plat-e Q carries insulating brackets e from which project laterally the respective carbon-holders c and (l. The holder 0 carries the upper or positive carbon a, while the holder designated 03 similarly carries the negative carbon 6. The inner extremities of a second pair of carbons a and b have been shown opposite those designated a and b and thelines joining the respective burning tips of the pairs of carbons will'be angularly disposed with respectto each other or, in other words, the flame between the carbon a and b tends to throw its light downwardly and toward the left in Fig. 1, although some of the light. will of course travel to the right, while the flame between the carbons a and b will di rect its rays downwardly and principally to the right When the lamp is burning, each arc. will normally remain at the inner ends of its respective set of carb ns, being held there, and not permitted to run in between the carbons, by electromagnetic action. In Fig:

1 the positive and negative carbons are, when desired, rigidly cla-med in their holders 'which are suitably insulated one from the other by the insulating bracket or bons may be displaceably arranged in such a manner that when the lamp is switched in, their free ends may contact, the are being struck when the ends of'the carbons subsequently separate. In Fig. 2 one means for so striking the arc has been shown; a helical actuating rod'l extending therebetween, said rod being mounted upon two pins m and n,

which pins are rotatable in fixed bearings 0 from the A small han le maybe and p which project downwardl supporting plate.

provided at the outer extremity of the pin m so that-the helical body of the rod may be rotated, which action will cause portions of the same to successively contact with. different points along the carbons a and b. Thus .as the pin m is rotated clockwise, as viewed in Fig. 3, thehelicalbody of the rod Z will engage the carbons a and b successively nearer to their holders, while vice versa when this body is rotated counter-clockwise the body Z will, in effect travel outwardly between the carbons, Spacing them apart. This helical rod may hence be used to space the carbons apart, regardless of the length of the latter and the lamp may therefore be switched on when the earbons are partly consumed.

What I- particularly desire to emphasize 1s the importance of providing a shielding plate above the carbons for steadying the flaming arc. Tfdesired, a globe h of glass or the like may also be used to inclose the under side of the are, but in many instances A flaming arc lamp comprising a pair of carbons arranged substantially horizontal, one above the other, the burning tip of the upper of said carbons normally projecting beyond that of the lower carbon, and a plate for steadying the flaming arc, said plate being disposed above the upper carbon and out of contact therewith.

KARL "ON DREGER.

Witnesses WOLDEMAR HAUPT, HENRY HASPER. 

